> UDP is not streamed but message based protocol. As WebSockets implement their transport layer over pure TCP, WebUDP could implement it's own layer over pure UDP for various reasons.

As soon as your message exceeds the MTU, things get complicated. Sure you can layer something to re-assemble, but if packets are dropping, this is going to start getting problematic really fast. And if packets are not dropping, then TCP shouldn't overly increase latency anyway.